Electrode for arc welding and process of making the same



Patented July 15,1930

EMIL

YORK

'WILLIAM'SCHWARTZ AND FREDERICK RICHARD KAIMER, EC'TICUT, ASSIGNORS TO GENERAL ELECTRIC COMPANY, A

or BRIDGEPORT, con- CORPORATION on NEW ELECTRODE non. Ano WELDING AND PROCESS or MAKING THE SAME,

No Drawing.

ing welding, the electrode is fed toward work, either manually or automatically, so as to maintain the arc length substantially constant.

It has been found that the facility with be maintained, and satiswhich an arc may factory metal deposited, is affected by certam elements or compounds applied to the must be welding electrode, for example, as a coating. lectrodes so coated are commonly designated as flux-coated electrodes, and coatin heretofore proposed vary from comparatively thick coatings tocoatings of inappreciable thickness, including in some cases mere traces sulating value, in elfect. like an insulating use of the elecf welding machine f enamel, which prevents the trode in an automatic arc of the type where the welding current is led into the moving electrode feed rolls or equivalent devices, such as rushes and the like. vWhere such electrodes are used for manual arc welding, the coating remoyed in order. to make a g electrical contact between the electrode and the electrode holder which the operator holds and welding; I

Objects of our invention areto produce an is deposited upon and welded to the work. Durl the through electrode,

- ,into bundles of short lengths for manual to use for weld- Application filed January 15, 1927. Serial No. 161,464.

improved electrode having satisfactory welding characteristics, and a process of manufacturing such electrodes which shall insure uniform results, which shall be relatively inexpensive to practice and which shall produce upon the electrode a relatively thin, but appreciable and substantially homogeneous coating, not easily rubbed off of the electrode, and which shall be conducting so that the elec- Anexample we have found satisfactory is as follows:

ear e Water 100 Sodium "silicate u 5 ed oxide of iron ime We prefer t boil the wire in the solution or a suflicient time to ect upon the wire, and we at present prefer the solution approximately five to eight hours. The wire is then simply removed from the solution, preferably wiped to remove any excess material adhering to its surface, and then allowed to dry, after which it is in condition for use. Where the wire as received from the manufacturer is wound on reels, andthe electrode is to be made up welding, .the win after drying is passed through straightening rolls and cut into short lengths. p

The sodium silicate in the bath acts to form eflicient medium for the suspension of All the ingredients con'tribute to give the bath an alkaline react-ion; which we produce the desired efin the appended The red oxide of iron and the lime are deposited on the surface of the wire, and cooperate to give the electrode good fluxing and arc stabilizing characterisfind very desirable.

ties.

The electrode wire made according to our process has a substantially uniform and homogeneous outer layer consisting principally of red oxide of iron: and lime, only a very small amount oflsodium silicate. By homogeneous in this description and in the appended claims we mean the intimate intermixture of the finely divided substances throughout the coating as distinguished from a coating made up of superposed layers. The surface of thevrod or wire has a recldis brown color, and, due to the coatingon the wire, it remains substantially free from corrosion after manufacture. The coating is quite adherent to the wire and can be rubbe off in a very slight amount only, so that the wire is relatively clean to handle, and-may be shipped and handled without damage to its coating with substantially thesame facility as bare wire. Whilewe have pound as used in the form of lime, found that calcium carbonate may One example of a bath which we have found satisfactory. utilizing both calcium oxide and calcium carbonate, comprises 100 parts of water, 5 partsof sodium silicate, 30 parts of we have red oxide of iron and 20 parts each of calcium oxide and calcium carbonate, and where claims we refer to a compound of calcium we intend to include either calcium oxide or calcium carbonate.

While in the foregoing description we have indicated as satisfactory proportions bath, it is to be understood th at some yaria- 1 iron to described the calcium com-- be used.

about 100 parts by weight of water, about 5 parts by weight of sodium silicate, about 30 parts by weight of red oxide of iron and about 10 parts by weight of lime, at a temperature substantially that of the boiling point of water, for a period of time sufficient to ,form on the electrode wire an appreciable thin homogeneous flux coating.

3. An electrode for arc welding comprising a metal wire having a substantially uniform, homogeneous, adherent flux coating containing iron oxide and calcium compound in about the ratio of 30 parts iron oxide to 40 parts of calcium compound. a

4. An electrode for arc welding comprish ing a metal wire having a substantially umform, homogeneous, adherent coating containing the following fluxing and arc-stabilizing a ents; about 30 parts red oxide of about 40 parts of calcium compound, said coating also containing an admixture of sodium silicate. i

In witness whereof, we have hereunto set our hands this 14th day of January, 1927. EMIL SVILLIAM SCHWARTZ. FREDERICK RICHARD KAIMER.

certain particular of the elements of our treating tions may be made without departing from our invention.

It will be understood that the electrode material which is treated may be put into the bath either in the form' of reels of wire or in the form of rods or strips of any desired length, and by the expression electrode wire in the appended claims we intend to include gpund wire or rod or other shapes of electrode rm. b What we cl aim as new and desire to secure 1. The process 'of manufacturing a coated arc welding electrode which comprises heating electrode wire in a mixture ,of substantially equalparts by weight vof red oxide of iron and a calcium compound suspend in about one and one-half times as much water containing a small for a time sufficient to produce upon a wire an preciable' thincoating. 2. The method of manufacture of a coated are welding electrode which comprises maintaining electrodewire in a bath composed Letters Patent of the United States is:

amount of sodium silicate 

